Watanabe Masahiko, Nakano Tsuyoshi, Shiotani Bunsyo, Matsushima-Hibiya Yuko, Kiuchi Makoto, Yukuhiro Fumiko, Kanazawa Takashi, Koyama Kotaro, Sugimura Takashi, Wakabayashi Keiji
Cancer Prevention Basic Research Project, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.
Comp Biochem Physiol A Mol Integr Physiol. 2004 Oct;139(2):125-31. doi: 10.1016/j.cbpb.2004.07.010.
The cabbage butterfly (Pieris rapae) produces pierisin-1, an apoptosis-inducing protein against mammalian cells. In order to clarify the biological role of pierisin-1 in P. rapae, its expression during developmental stages was examined. Low levels of pierisin-1 mRNA and protein were detected in first-instar larvae. During growth until the fifth-instar larval stage, the amounts of the mRNA steadily increased to reach about 50-100 times the initial level. Then it rapidly decreased before pupation. The levels of mRNA in the pupae and the adults were as low as in the first-instar larvae. Levels of pierisin-1 protein also increased around 100 times from the first-instar to the fifth-instar larvae and then gradually decreased by over 90% during the pupal stage. Immunostaining of pierisin-1 demonstrated the protein to be mainly located in fat bodies of fifth-instar larvae and early-phase pupae. Although the staining intensity was low, fat bodies of early instars of the larvae and adults were also found to be positive. Moreover, examination of isolated fat body and other tissue samples of the insects were consistent with the above observations. Thus, the results indicate that mRNA of pierisin-1 was highly expressed in late stages of larvae, and that the protein accumulated in fat bodies where it persists during pupation.
菜粉蝶（粉纹夜蛾）会产生pierisin-1，这是一种针对哺乳动物细胞的诱导凋亡蛋白。为了阐明pierisin-1在菜粉蝶中的生物学作用，研究了其在发育阶段的表达情况。在一龄幼虫中检测到低水平的pierisin-1 mRNA和蛋白质。在生长至五龄幼虫阶段的过程中，mRNA的量稳步增加，达到初始水平的约50至100倍。然后在化蛹前迅速下降。蛹和成虫中的mRNA水平与一龄幼虫中的一样低。从一龄幼虫到五龄幼虫，pierisin-1蛋白的水平也增加了约100倍，然后在蛹期逐渐下降超过90%。pierisin-1的免疫染色表明该蛋白主要位于五龄幼虫和早期蛹的脂肪体中。尽管染色强度较低，但幼虫和成虫早期龄期的脂肪体也呈阳性。此外，对昆虫分离的脂肪体和其他组织样本的检测与上述观察结果一致。因此，结果表明pierisin-1的mRNA在幼虫后期高度表达，并且该蛋白在脂肪体中积累，并在化蛹期间持续存在。
